The Study On Daptability Of Water Injection Technology In Low Permeability And High Pour Point Oil Reservoir

In heterogeneous multi-reservoir oil fields of water injection development, in order to ease the interlamination contradictions of uneven water absorbency, make each layer can play better production potential, thus developed a separated zone water injection technology. Trip in the packer in the injection wells, separate the reservoirs that are very different, and then stratified water distribution with the water injection allocator, so that the water injection rate of the high permeability layer has been controlled, the water injection rate of low-to-moderate permeability reservoir has been strengthened, so that all types of the reservoirs can play a role.Haian oilfield is the low permeability and high pour point oil field, the low permeability and high pour point oil fields have low injection pressure, are difficult to waterflood, the lack of injection is serious, the water injection technology support is difficult, high system investment, low efficiency, downhole conditions in the water injection development process is increasingly complex, development needs are constantly refined, must be based on the existing mature separate injection technology, by development and introduction of technology,conduct the technology integration and support, strengthening the relevance of the process to expand the scope of application of technology,to improve the oilfield overall level of injection process.The paper started from the separate injection process of the injection wells, evaluate the present conventional combinations of eccentric separate injection column and adaptability of the test modification technology; evaluate from the technological characteristics、the feasibility analysis of application, the main instrument technical parameters and working principle, the test modification technical angle of bridge eccentric separate injection technology, the separate injection process of deep and inclined well and test modification linkage separate injection process. Analyzed the characteristics and application environments of the five separate injection processes, provide a theoretical basis for the Haian oilfield water injection process. Haian oil field should used the separate injection technology adapt to the deep well high temperature, the bridge eccentric water distribution column can be used for deep separate injection. To realize the function of single-layer flow test of stratified injection wells, stop destination layer but kept wells working when stratified stress test,developed bridge eccentric separate injection process and test modification technology. Bridge eccentric separate injection process improve it on the basis of original eccentric water injection allocators that have bridge channel which can realize the benefits of single-layer separate measuring, make it meet the needs of the deployment of stratified flow. When measured hierarchical pressure, not only can achieve single-layer separate measure, but also without needing the eccentric packer, not only improve the accuracy of the hierarchical data, but also improve the efficiency of hierarchical test.Determine the injection water quality standards by water injection experiments.For the augmented injection technology of the injection wells, this paper researched Haian oilfield augmented injection technology of decompression by acid fracturing and fracturing augmented injection technology. By studying reservoir properties, analyzed the reasons of lack of injection of injection wells; experiment research on reservoir sensitivity, preferred a targeted acid system and acidification construction process, based on reservoir characteristics. The natural water absorption capacity of Haian oilfield Fu Ⅲ is low, the reservoir pore throat is small. Experiments about reservoir sensitivity show that there is medium weak speed-sensitive, moderate to strong water-sensitive, middle-weak acid sensitivity, no alkali sensitivity in Fu Ⅲ. Select high temperature retarder acid formula to reservoir. Site implementation results show:The preferred acid system is highly targeted, and the supporting technology is mature. After finishing acidification construction, the oil pressure of injection wells has substantially decreased, and the injection flow rate achieved the requirements of geology injection proration.In the technology of augmented injection by fracturing, analyze and evaluate the various factors affecting the fracturing effect, in which reservoir geological conditions are basic affecting factors; determining screening of the fracturing fluid, the selection of proppant, the amount of augmented sand, displacement and other construction parameters has important effect to the postfracture response, about Haian oilfield the paper focused on describing the selection of fracturing fluid. Fracturing technology is also an important factor to affect the fracture stimulation effect. For the different characteristic reservoir, must adopt suitable technology, in order to ensure the successful implementation of the fracturing design and achieve better results of increasing production. The overall fracturing effect of Haian oilfield is obvious, shows that the adoptive fracturing fluid system is suitable.The water injection technology covers a wide range of content, by looking for a large number of documents, conducted a comprehensive analysis and study field application, from system engineering point of view, according to the actual situation of the oil field water injection process, combined with the development trend of IT, fully draw lessons from previous research ideas and approaches,for the actual problems and needs of Haian oilfield, make the evaluation about adaptability and supporting technologies research of water injection technology to low permeability and high pour point reservoir.